Q: How do I make my Video HD in Sony Vegas?
Answer: You can't magically turn low resolution Standard Definition video into HD Video.
If you want to make 1080p HD Video, then you must create your video with a 1080i/p HD Camera.
You can render a video to HD settings if you like, but in many cases it will just be making the video look worse.
A better option is to render at 480p Wiidescreen Settings with a Higher Bit Rate like 4, 5 or 6Mbps.
High Definition 1080p Video is up to SIX times larger than Standard Defintion video - which means there are 6x times more pixels on the screen. So if you try to convert an older SD Video that isn't very good in the first place, what it is actually doing is blowing UP any imperfections in the original video. That equals aweful looking video.
The only people that can really convert older SD Video into HD, are Hollywood Studios who have access to very powerful computers that clean up the image first during the re-mastering process.